US4471630A - Cooling system having combination of compression and absorption type units - Google Patents

Cooling system having combination of compression and absorption type units Download PDF

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US4471630A
US4471630A US06/461,567 US46156783A US4471630A US 4471630 A US4471630 A US 4471630A US 46156783 A US46156783 A US 46156783A US 4471630 A US4471630 A US 4471630A
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refrigeration unit
type refrigeration
cooling
medium
absorption type
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Shigeo Sugimoto
Ryohei Minowa
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Hitachi Ltd
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Hitachi Ltd
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B25/00—Machines, plants or systems, using a combination of modes of operation covered by two or more of the groups F25B1/00 - F25B23/00
    • F25B25/02—Compression-sorption machines, plants, or systems

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  • the present invention relates to a cooling system including a compression type refrigeration unit and an absorption type refrigeration unit, suitable for use in air conditioners, for chilling of fluids or goods, and so forth.
  • the refrigeration units A, B are constructed as separate or independent refrigeration units or, alternatively, arranged in a so-called series system in which the medium 15 to be cooled (cold water) of a comparatively high temperature is cooled down by the evaporator 5 of the absorption type refrigeration unit B and is further cooled by the evaporator 4 of the compression type refrigeration unit A.
  • the cooling medium 14 (cooling water) is circulated through the condenser 2 of the compression type refrigeration unit A and the absorber 6 and the condenser 8 of the absorption type refrigeration unit B.
  • the compression type refrigeration unit A provides greater energy saving effect than the absorption type refrigeration unit B, so that the above-explained series arrangement is not preferred from the view point of energy conservation.
  • an object of the invention is to provide a cooling system having a combination of a compression type refrigeration unit and an absorption type refrigeration unit, in which the compression type refrigeration unit and the absorption type refrigeration unit are combined in such a manner so as to attain an efficient use of energy, i.e. energy conservation.
  • Another object of the invention is to provide a cooling system, improved to provide a greater range of operation in which the compression type refrigeration unit can operate without surging.
  • a cooling system including a compression type refrigeration unit and an absorption type refrigeration unit
  • the compression type refrigeration unit includes: a compressor having a capacity control mechanism; a condenser for cooling and condensing a refrigerant gas compressed by the compressor through heat exchange between the refrigerant gas and a cooling medium circulated through the condenser; and an evaporator into which the condensed refrigerant is introduced through an expansion means, with the refrigerant then being evaporated and cooling a medium to be cooled by the latent heat derived from the evaporation.
  • the absorption type refrigeration unit includes: a generator having a capacity control mechanism and adapted to heat a solution thereby to generate the vapor of a refrigerant and a strong solution; a condenser in which the vapor of refrigerant generated in the generator is cooled and condensed through heat exchange with a cooling medium; an evaporator in which the refrigerant condensed in the condenser being evaporated and cooling a medium to be cooled by the latent heat derived from the evaporation; an absorber in which the vapor of refrigerant generated in the evaporator is absorbed by a strong solution generated in the generator to thereby form a weak solution; and a pump adapted to feed the weak solution generated in the absorber to the generator.
  • the compression type refrigeration unit and the absorption type refrigeration unit are connected to each other in such a manner that at least the medium to be cooled out of the medium to be cooled and the cooling medium first flow into the compression type refrigeration unit and, after coming out of the compression type refrigeration unit, into the absorption type refrigeration unit.
  • FIG. 1 is a schematic diagram of a conventional cooling system
  • FIG. 2 is a schematic diagram of a cooling system in accordance with one embodiment of the present invention.
  • FIG. 3 is a graphical illustration of the relationship between a required cooling load and a valve opening degree in a compression-type refrigeration unit and an absorption-type refrigeration unit.
  • a compression type refrigeration unit A has a centrifugal compressor 1, condenser 2, expansion means 3 and an evaporator 4, while an absorption type refrigeration unit B is constituted by an evaporator 5, absorber 6, generator 7 and a condenser 8.
  • Capacity control valves 9 annexed to the compressor 1, are adapted to be driven by a motor 10.
  • a temperature detector 11 is disposed in the passage 12 for medium to be cooled (cold water) connected between the evaporator 4 of the compression type refrigeration unit A and the evaporator 4 of the absorption type refrigeration unit B or at the outlet of the evaporator 4.
  • a temperature controller 13 is connected to the temperature detector 11, motor 10 and a control valve 17. The temperature controller 13 is adapted to generate a signal for maintaining a substantially constant temperature of the cold water, with the motor 10 and the control valve 17 being operated in accordance with this signal.
  • a cooling medium (cooling water) 14 is circulated through the condenser 2 of the compression type refrigeration unit A and the absorber 6 and the condenser 8 of the absorption type refrigeration unit B successively, while a medium to be cooled (cold water) 15 is circulated through the evaporator 4 of the compression type refrigeration unit A and the evaporator 5 of the absorption type refrigeration unit B.
  • a control valve 17 is disposed in the passage 16 for supplying a heating medium.
  • a prime mover 18 drives the compressor 1, with the absorption type refrigeration unit B further including a heat exchanger 19 and a pump P.
  • Freon 11 R11
  • Freon 12 R12
  • the gas of this refrigerant is compressed by the centrifugal compressor 1 which is driven by the prime mover 18.
  • the compressed gas is introduced into the condenser 2 and is cooled and condensed by the cooling medium (cooling water) circulated through the condenser 2.
  • the refrigerant condensed into liquid phase in the condenser is then introduced, through an expansion means 3, into an evaporator 4 where the refrigerant is evaporated and cools the medium 15 to be cooled circulated through the evaporator 4 by the latent heat derived from the evaporation.
  • the refrigerant gas generated as a result of the evaporation is introduced into the centrifugal compressor 1 through a capacity control effected by the capacity control valves 9 which, in turn, are driven by the motor 10 under the control of the temperature controller 13. Then, the refrigerant is compressed and the refrigeration cycle explained above is repeated.
  • the absorption type refrigeration unit B makes use of an aqueous solution of lithium bromide.
  • the solution is heated by the heating medium which is supplied into the generator 7 from the heating medium supplying passage 16 at a flow rate controlled by a control valve 17. Consequently, the water serves as the refrigerant for the absorption type refrigerant vapor (water vapor) and strong solution of lithium bromide.
  • the refrigerant vapor is introduced into the condenser 8 so as to be cooled and condensed by the cooling medium (cooling water) circulated through the condenser 8.
  • the refrigerant (water) generated as a result of condensation in the condenser 8 is then introduced into the evaporator 5 being evaporated and cooling the medium 15 to be cooled circulated through the evaporator 5 by the latent heat derived from the evaporation.
  • the evaporated refrigerant is then introduced into the absorber 6 which receives also the strong solution generated in the generator 7 through the heat exchanger 19.
  • the absorber 6 the refrigerant vapor and the strong solution are cooled by the cooling medium (cooling water) 14 circulated through the absorber so that the refrigerant vapor is absorbed by the strong solution to form a weak solution.
  • the weak solution generated in the absorber is returned to the generator 7 through the heat exchanger 19 by means of the pump P, and the cycle explained above is repeated.
  • Freon 11 (R11) or Freon 12 (R12) is used as the refrigerant for the compression type refrigeration unit A, while an aqueous solution of lithium bromide is used as the refrigerant for the absorption type refrigeration unit B.
  • These refrigerants are not exclusive and the cooling system of the invention can use any suitable other refrigerant or solution.
  • the cooling medium (cooling water) is gradually heated as it flows through the condenser 2 of the compression type refrigeration unit A, and the absorber 6 and the condenser 8 of the absorption type refrigeration unit B.
  • the thus heated cooling water is introduced to a cooling tower (not shown) where it is cooled and then supplied again to the cooling system in which the compression type refrigeration unit A and the absorption type refrigeration unit B are combined, so that the refrigeration cycles are repeated in the manner explained above.
  • the medium 15 to be cooled (cold water) is cooled through the evaporator 4 of the compression type refrigeration unit A.
  • the temperature of the medium 15 to be cooled (cold water) is detected by the temperature detector 11 at the outlet side of the evaporator 4.
  • the temperature detector 11 produces a signal representative of the temperature of the medium 15 to be cooled to the temperature controller 13 which, in turn, effects the capacity control of the compressor 1 through adjustment of the capacity control valves 9 which are driven by the motor 10 under the control of the temperature controller 13, to thereby control the flow rate of the refrigerant introduced from the evaporator 4 into the centrifugal compressor so as to maintain a constant temperature of the medium 15 to be cooled.
  • the cooled medium 15 is then circulated through and further cooled in the evaporator 5 of the absorption type refrigeration unit B and is then introduced to the cooling load (not shown) so as to cool the same.
  • the cooled medium (cold water), which is heated to a higher temperature as a result of cooling of the load, is then returned to the evaporator 4 of the compression type refrigeration unit A and the above described cycle is repeated.
  • the temperature difference between the cooling water 14 and the cold water 15 is much smaller than that in the conventional system shown in FIG. 1 so that the energy is remarkably conserved in the compression type refrigeration A in proportion to the reduction in the temperature difference.
  • the cooling power of the compression type refrigeration unit A is smaller than the demanded cooling power
  • the temperature of the cold medium 15 is raised.
  • the cooling power of the compression type refrigerator A is excessive, the temperature of the cold medium 15 is lowered.
  • This variation is detected by the temperature detector 11, and the temperature controller 13 operates in response to the output from the temperature detector 11 so as to control the motor 10 for driving the capacity control valves 9 and also the control valve 17.
  • the cooling powers of the refrigeration units A and B to make the actual cooling power coincide with the demanded cooling load.
  • the control is made such that the cooling powers the compression type refrigeration unit A and the absorption type refrigeration unit B are varied in response to a change in the demanded cooling power in a manner shown more clearly in FIG. 3.
  • the angle of the capacity control valves 9 of the compressor are changed by the temperature controller 13 substantially in proportion to the increase or decrease of the cooling load.
  • the opening degree of the capacity control valves 9 is increased to 100% so that the compression type refrigeration unit A operates at the rated power, i.e. with full load.
  • the temperature of the medium to be cooled (cold water) is increased so that the control valve 17 of the absorption type refrigeration unit B is opened by the action of the temperature controller 13 so that the heating medium is introduced into the generator 8 through the heating medium supply passage 16.
  • the absorption type refrigeration unit B operates with its cooling power varied by a change in the opening degree of the control valve 17 in accordance with the increase or decrease of the part of the cooling exceeding the above-mentioned predetermined limit.
  • the compression type refrigeration unit A operates with 100% opening of the capacity control valves 9, i.e. at the rated or full load, while the absorption type refrigeration unit B operates in such a manner that its capacity or cooling power is increased or decreased in accordance with the part of the cooling load above the predetermined limit.
  • the compression type refrigeration unit A can operate with its rated load over almost entire part of operation period of the cooling system, except the case where the cooling load is very small. According to the invention, it is thus possible to operate the compression type refrigeration unit A at a remarkably high efficiency.
  • the temperature controller 13 is constructed to maintain a substantially constant temperature of the cold medium flowing from the evaporator 4 of the compression type refrigeration unit A and the evaporator 5 of the absorption type refrigeration unit B, i.e. a substantially constant temperature of the cold medium coming out from the compression type refrigeration unit A.
  • this control is made in such a manner as to maintain a constant temperature of the cold medium coming out of the whole cooling system, i.e. at the outlet of the absorption type refrigeration unit B.
  • the temperature of the cold medium coming from the compression type refrigeration unit A becomes considerably lower than that obtained in the operation at the rated load.
  • control valve (not shown) which make both of the medium to be cooled (cold water) and the cooling medium (cooling water) flow by-passing or detouring the absorption type refrigeration unit B when the latter is not operating due to a small cooling load demand.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Devices That Are Associated With Refrigeration Equipment (AREA)
  • Sorption Type Refrigeration Machines (AREA)

Abstract

A cooling system including a compression refrigeration unit and an absorption refrigeration unit, with the compression refrigeration unit including a compressor having a capacity control mechanism; a condenser for cooling and condensing a compressed refrigerant gas through a heat exchange between the refrigerant gas and a cooling medium circulated through the condenser; and an evaporator into which the condensed refrigerant is introduced through an expansion means so as to be evaporated and cool a medium by the latent heat derived from evaporation. The absorption refrigeration unit includes a generator having a capacity control mechanism for heating a solution to generate a vapor of a refrigerant and a strong solution; a condenser in which the vapor of refrigerant generated in the generator is cooled and condensed an evaporator in which the refrigerant in the condenser is evaporated and cools a medium to be cooled by latent heat from the evaporation; an absorber in which the vapor of refrigerant is absorbed by the strong solution generated and forms a weak solution; and a pump for feeding the weak solution to the generator. The compression refrigeration unit and the absorption refrigeration unit are connected so that at least the medium to be cooled and the cooling medium first flows into the compression refrigeration unit and then into the absorption refrigeration unit.

Description

BACKGROUND OF THE INVENTION
The present invention relates to a cooling system including a compression type refrigeration unit and an absorption type refrigeration unit, suitable for use in air conditioners, for chilling of fluids or goods, and so forth.
As shown in FIG. 1, in a known cooling system including a compression type refrigeration unit generally designated by the reference character A and an absorption type refrigeration unit generally designated by the reference character B, the refrigeration units A, B are constructed as separate or independent refrigeration units or, alternatively, arranged in a so-called series system in which the medium 15 to be cooled (cold water) of a comparatively high temperature is cooled down by the evaporator 5 of the absorption type refrigeration unit B and is further cooled by the evaporator 4 of the compression type refrigeration unit A. On the other hand, the cooling medium 14 (cooling water) is circulated through the condenser 2 of the compression type refrigeration unit A and the absorber 6 and the condenser 8 of the absorption type refrigeration unit B. However, when the temperature difference between the cold water 15 and the cooling water 14 is small, the compression type refrigeration unit A provides greater energy saving effect than the absorption type refrigeration unit B, so that the above-explained series arrangement is not preferred from the view point of energy conservation.
SUMMARY OF THE INVENTION
Accordingly, an object of the invention is to provide a cooling system having a combination of a compression type refrigeration unit and an absorption type refrigeration unit, in which the compression type refrigeration unit and the absorption type refrigeration unit are combined in such a manner so as to attain an efficient use of energy, i.e. energy conservation.
Another object of the invention is to provide a cooling system, improved to provide a greater range of operation in which the compression type refrigeration unit can operate without surging.
To this end, according to the invention, there is provided a cooling system including a compression type refrigeration unit and an absorption type refrigeration unit, wherein the compression type refrigeration unit includes: a compressor having a capacity control mechanism; a condenser for cooling and condensing a refrigerant gas compressed by the compressor through heat exchange between the refrigerant gas and a cooling medium circulated through the condenser; and an evaporator into which the condensed refrigerant is introduced through an expansion means, with the refrigerant then being evaporated and cooling a medium to be cooled by the latent heat derived from the evaporation. The absorption type refrigeration unit includes: a generator having a capacity control mechanism and adapted to heat a solution thereby to generate the vapor of a refrigerant and a strong solution; a condenser in which the vapor of refrigerant generated in the generator is cooled and condensed through heat exchange with a cooling medium; an evaporator in which the refrigerant condensed in the condenser being evaporated and cooling a medium to be cooled by the latent heat derived from the evaporation; an absorber in which the vapor of refrigerant generated in the evaporator is absorbed by a strong solution generated in the generator to thereby form a weak solution; and a pump adapted to feed the weak solution generated in the absorber to the generator. The compression type refrigeration unit and the absorption type refrigeration unit are connected to each other in such a manner that at least the medium to be cooled out of the medium to be cooled and the cooling medium first flow into the compression type refrigeration unit and, after coming out of the compression type refrigeration unit, into the absorption type refrigeration unit.
These and other objects, features and advantages of the invention will become clear from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a conventional cooling system;
FIG. 2 is a schematic diagram of a cooling system in accordance with one embodiment of the present invention; and
FIG. 3 is a graphical illustration of the relationship between a required cooling load and a valve opening degree in a compression-type refrigeration unit and an absorption-type refrigeration unit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 2, a compression type refrigeration unit A has a centrifugal compressor 1, condenser 2, expansion means 3 and an evaporator 4, while an absorption type refrigeration unit B is constituted by an evaporator 5, absorber 6, generator 7 and a condenser 8. Capacity control valves 9 annexed to the compressor 1, are adapted to be driven by a motor 10.
A temperature detector 11 is disposed in the passage 12 for medium to be cooled (cold water) connected between the evaporator 4 of the compression type refrigeration unit A and the evaporator 4 of the absorption type refrigeration unit B or at the outlet of the evaporator 4. A temperature controller 13 is connected to the temperature detector 11, motor 10 and a control valve 17. The temperature controller 13 is adapted to generate a signal for maintaining a substantially constant temperature of the cold water, with the motor 10 and the control valve 17 being operated in accordance with this signal.
A cooling medium (cooling water) 14 is circulated through the condenser 2 of the compression type refrigeration unit A and the absorber 6 and the condenser 8 of the absorption type refrigeration unit B successively, while a medium to be cooled (cold water) 15 is circulated through the evaporator 4 of the compression type refrigeration unit A and the evaporator 5 of the absorption type refrigeration unit B. A control valve 17 is disposed in the passage 16 for supplying a heating medium. A prime mover 18 drives the compressor 1, with the absorption type refrigeration unit B further including a heat exchanger 19 and a pump P.
The cooling system of the described embodiment operates in the following manner:
In this embodiment, Freon 11 (R11) or Freon 12 (R12) is used as the refrigerant circulated in the compression type refrigeration unit A. The gas of this refrigerant is compressed by the centrifugal compressor 1 which is driven by the prime mover 18. The compressed gas is introduced into the condenser 2 and is cooled and condensed by the cooling medium (cooling water) circulated through the condenser 2. The refrigerant condensed into liquid phase in the condenser is then introduced, through an expansion means 3, into an evaporator 4 where the refrigerant is evaporated and cools the medium 15 to be cooled circulated through the evaporator 4 by the latent heat derived from the evaporation. The refrigerant gas generated as a result of the evaporation is introduced into the centrifugal compressor 1 through a capacity control effected by the capacity control valves 9 which, in turn, are driven by the motor 10 under the control of the temperature controller 13. Then, the refrigerant is compressed and the refrigeration cycle explained above is repeated.
On the other hand, the absorption type refrigeration unit B makes use of an aqueous solution of lithium bromide. In the generator 7, the solution is heated by the heating medium which is supplied into the generator 7 from the heating medium supplying passage 16 at a flow rate controlled by a control valve 17. Consequently, the water serves as the refrigerant for the absorption type refrigerant vapor (water vapor) and strong solution of lithium bromide. The refrigerant vapor is introduced into the condenser 8 so as to be cooled and condensed by the cooling medium (cooling water) circulated through the condenser 8. The refrigerant (water) generated as a result of condensation in the condenser 8 is then introduced into the evaporator 5 being evaporated and cooling the medium 15 to be cooled circulated through the evaporator 5 by the latent heat derived from the evaporation. The evaporated refrigerant is then introduced into the absorber 6 which receives also the strong solution generated in the generator 7 through the heat exchanger 19. In the absorber 6, the refrigerant vapor and the strong solution are cooled by the cooling medium (cooling water) 14 circulated through the absorber so that the refrigerant vapor is absorbed by the strong solution to form a weak solution. The weak solution generated in the absorber is returned to the generator 7 through the heat exchanger 19 by means of the pump P, and the cycle explained above is repeated.
In the described embodiment, Freon 11 (R11) or Freon 12 (R12) is used as the refrigerant for the compression type refrigeration unit A, while an aqueous solution of lithium bromide is used as the refrigerant for the absorption type refrigeration unit B. These refrigerants, however, are not exclusive and the cooling system of the invention can use any suitable other refrigerant or solution.
The cooling medium (cooling water) is gradually heated as it flows through the condenser 2 of the compression type refrigeration unit A, and the absorber 6 and the condenser 8 of the absorption type refrigeration unit B. The thus heated cooling water is introduced to a cooling tower (not shown) where it is cooled and then supplied again to the cooling system in which the compression type refrigeration unit A and the absorption type refrigeration unit B are combined, so that the refrigeration cycles are repeated in the manner explained above. The medium 15 to be cooled (cold water) is cooled through the evaporator 4 of the compression type refrigeration unit A. The temperature of the medium 15 to be cooled (cold water) is detected by the temperature detector 11 at the outlet side of the evaporator 4. The temperature detector 11 produces a signal representative of the temperature of the medium 15 to be cooled to the temperature controller 13 which, in turn, effects the capacity control of the compressor 1 through adjustment of the capacity control valves 9 which are driven by the motor 10 under the control of the temperature controller 13, to thereby control the flow rate of the refrigerant introduced from the evaporator 4 into the centrifugal compressor so as to maintain a constant temperature of the medium 15 to be cooled. The cooled medium 15 is then circulated through and further cooled in the evaporator 5 of the absorption type refrigeration unit B and is then introduced to the cooling load (not shown) so as to cool the same. The cooled medium (cold water), which is heated to a higher temperature as a result of cooling of the load, is then returned to the evaporator 4 of the compression type refrigeration unit A and the above described cycle is repeated.
In the rated operation of the cooling system A, the temperature difference between the cooling water 14 and the cold water 15 is much smaller than that in the conventional system shown in FIG. 1 so that the energy is remarkably conserved in the compression type refrigeration A in proportion to the reduction in the temperature difference.
On the other hand, when the cooling power of the compression type refrigeration unit A is smaller than the demanded cooling power, the temperature of the cold medium 15 is raised. To the contrary, if the cooling power of the compression type refrigerator A is excessive, the temperature of the cold medium 15 is lowered. This variation is detected by the temperature detector 11, and the temperature controller 13 operates in response to the output from the temperature detector 11 so as to control the motor 10 for driving the capacity control valves 9 and also the control valve 17. As a result of this operation, the cooling powers of the refrigeration units A and B to make the actual cooling power coincide with the demanded cooling load. In this case, the control is made such that the cooling powers the compression type refrigeration unit A and the absorption type refrigeration unit B are varied in response to a change in the demanded cooling power in a manner shown more clearly in FIG. 3.
Namely, while the cooling load is still small, only the compression type refrigeration unit A operates while the operation of the absorption type refrigeration unit B is suspended. According to this arrangement, the angle of the capacity control valves 9 of the compressor are changed by the temperature controller 13 substantially in proportion to the increase or decrease of the cooling load. As the cooling load demand increased to reach a predetermined limit, the opening degree of the capacity control valves 9 is increased to 100% so that the compression type refrigeration unit A operates at the rated power, i.e. with full load. Then, as the cooling load demand is increased to exceed the above-mentioned predetermined limit, the temperature of the medium to be cooled (cold water) is increased so that the control valve 17 of the absorption type refrigeration unit B is opened by the action of the temperature controller 13 so that the heating medium is introduced into the generator 8 through the heating medium supply passage 16. As a result, the absorption type refrigeration unit B operates with its cooling power varied by a change in the opening degree of the control valve 17 in accordance with the increase or decrease of the part of the cooling exceeding the above-mentioned predetermined limit. Namely, as the cooling load exceeds the predetermined limit which is shown by the vertical broken line at the center of FIG. 3, the compression type refrigeration unit A operates with 100% opening of the capacity control valves 9, i.e. at the rated or full load, while the absorption type refrigeration unit B operates in such a manner that its capacity or cooling power is increased or decreased in accordance with the part of the cooling load above the predetermined limit.
Therefore, provided that the ratio of the cooling power of the compression type refrigeration unit A to the total cooling power provided by the compression type refrigeration unit A and the absorption type refrigeration unit B is selected adequately, the compression type refrigeration unit A can operate with its rated load over almost entire part of operation period of the cooling system, except the case where the cooling load is very small. According to the invention, it is thus possible to operate the compression type refrigeration unit A at a remarkably high efficiency.
The temperature controller 13 is constructed to maintain a substantially constant temperature of the cold medium flowing from the evaporator 4 of the compression type refrigeration unit A and the evaporator 5 of the absorption type refrigeration unit B, i.e. a substantially constant temperature of the cold medium coming out from the compression type refrigeration unit A. Conventionally, this control is made in such a manner as to maintain a constant temperature of the cold medium coming out of the whole cooling system, i.e. at the outlet of the absorption type refrigeration unit B. However, when the cooling power demand is small or the operation of the absorption type refrigeration unit B is suspended, the temperature of the cold medium coming from the compression type refrigeration unit A becomes considerably lower than that obtained in the operation at the rated load. In general, when the compression ratio is increased beyond a predetermined value, a phenomenon called "surging" takes place in the centrifugal compressor to produce large noise and vibration. The fact that the temperature difference between the cooling medium and the cold medium becomes large when the load is much smaller than the rated capacity means that the margin for surging is disadvantageously decreased. However, according to the invention, the temperature difference between the cooling medium and the cold medium is not increased even when the load is small, so that the above-described inconvenience is advantageously avoided.
In the cooling system of the invention it is preferred to provide a control valve (not shown) which make both of the medium to be cooled (cold water) and the cooling medium (cooling water) flow by-passing or detouring the absorption type refrigeration unit B when the latter is not operating due to a small cooling load demand.

Claims (8)

What is claimed is:
1. A cooling system including a compression type refrigeration unit and an absorption type refrigeration unit, said compression type refrigeration unit includes: a compressor having a capacity controlled mechanism; a condenser means for cooling and condensing a refrigerant gas compressed by said compressor through a heat exchange between said refrigerant gas and a cooling medium circulated through said condensor means; and an evaporator means for receiving the condensed refrigerant through an expansion means, the refrigerant being evaporated and cooling a medium to be cooled by lattent heat derived from the evaporation; said absorption type refrigeration unit includes: a generator means having a capacity control mechanism for heating a solution to thereby generate a vapor of a refrigerant and a strong solution; a condensor means for cooling said vapor of said refrigeran generated in said generator and for condensing said vapor through a heat exchange with a cooling medium; an evaporator means for evaporating said refrigerant condensed in said condensor means and for cooling a medium to be cooled by latent heat derived from the evaporation; and an absorber means for absorbing the vapor of said refrigerant generated in said evaporator means by said strong solution generated in said generator means to thereby form a weak solution; and a pump means for feeding the weak solution generated in the absorber means to said generator means; and means for connecting said compression type refrigeration unit and said absorption type refrigeration unit to each other in such a manner that at least said medium to be cooled and said cooling medium first flows into said compression type refrigeration unit and, after coming out of said compression type refrigeration unit, into said absorption type refrigeration unit.
2. A cooling system according to claim 1, wherein said connecting means enables the cooling medium to sequentially flow through said condenser means of said compression type refrigeration unit, absorber means of said absorption type refrigeration unit, and then through said condenser means of said absorption type refrigeration unit.
3. A cooling system according to claim 1, wherein said connecting means enables the medium to be cooled to first flow through said evaporator means of said compression type refrigeration unit and then through said absorption type refrigeration unit.
4. A cooling system according to claim 2, wherein said connecting means enables the medium to be cooled to flow first through said evaporator means of said compression type refrigeration unit and then through said absorption type refrigeration unit.
5. A cooling system according to claim 1, further comprising a temperature detector means disposed at an outlet for said medium to be cooled for detecting the temperature thereof, and a temperature controller means connected to said temperature detector means for cotrolling the operation of said capacity control mechanism in said compression type refrigeration unit and said absorption type refrigeration unit.
6. A cooling system according to claim 5, further comprising means for operating said compression type refrigeration unit only when the cooling power demand is less than a predetermined limit within the total cooling power of said cooling system and for starting operation of said absorption type refrigeration unit to increase the cooling power when said cooling power demand is increased beyond said predetermined limit.
7. A cooling system according to claim 6, wherein said temperature controller means operates in response to a signal from said temperature detector means in such a manner so as to operate said capacity control mechanism of said compression type refrigeration unit to limit the capacity of the latter, when the cooling power demand does not reach a predetermined limit within the cooling capacity of said cooling system.
8. A cooling system according to claim 6, wherein said connecting means enables the cooling medium to flow through said condenser means of said compression type refrigeration unit, then through said absorber means of said absorption type refrigeration unit, and then through said condenser means of said absorption type refrigeration unit, while said medium to be cooled flows first through said evaporator means of said compression type refrigeration unit and then through the evaporator means of said absorption type refrigeration unit.
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JP (1) JPS58129172A (en)

Cited By (34)

* Cited by examiner, † Cited by third party
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US4586344A (en) * 1984-10-23 1986-05-06 Dm International Inc. Refrigeration process and apparatus
EP0181137A3 (en) * 1984-11-05 1987-02-04 Calmac Manufacturing Corporation Method of cyclic air conditioning with cogeneration of ice
US4745768A (en) * 1987-08-27 1988-05-24 The Brooklyn Union Gas Company Combustion-powered refrigeration with decreased fuel consumption
WO1988008107A1 (en) * 1987-04-09 1988-10-20 Scherer, Frank, J. Integrated cascade refrigeration system
US4966007A (en) * 1989-05-12 1990-10-30 Baltimore Aircoil Company, Inc. Absorption refrigeration method and apparatus
US5018367A (en) * 1988-08-04 1991-05-28 Hitachi, Ltd. Cooling energy generator with cooling energy accumulator
US5038574A (en) * 1989-05-12 1991-08-13 Baltimore Aircoil Company, Inc. Combined mechanical refrigeration and absorption refrigeration method and apparatus
USRE34030E (en) * 1987-04-09 1992-08-18 Frank J. Scherer Integrated cascade refrigeration system
US5163302A (en) * 1991-10-21 1992-11-17 General Motors Corporation Air conditioning system with precooler
US5212961A (en) * 1991-10-15 1993-05-25 Graf William J Dual cycle water chiller
US6141987A (en) * 1997-01-20 2000-11-07 Gaz De France Absorption refrigerating system and working mixture for said system
RU2344357C1 (en) * 2007-04-12 2009-01-20 ГОУ ВПО "Южно-Российский государственный университет экономики и сервиса" (ЮРГУЭС) Absorption/compression refrigeration unit
WO2010054537A1 (en) * 2008-11-17 2010-05-20 Su Qingquan Heat pump cycle system and combined supplying method of cold and heat
WO2011089338A3 (en) * 2010-01-19 2011-10-27 Atoll Energy Thermal power upgrade facility
KR101093919B1 (en) 2010-01-15 2011-12-13 엘지전자 주식회사 Vertical absorption chiller
US20120011871A1 (en) * 2010-07-13 2012-01-19 Cameron International Corporation Compressor waste heat driven cooling system
US20120031122A1 (en) * 2009-04-14 2012-02-09 Huayu Li Method to improve heating temperature of heat pump and second-type high temperature absorption heat pump
WO2013021323A1 (en) 2011-08-05 2013-02-14 Innovation Factory S.R.L. Heat pump system and method of cooling and/or heating by means of said system
CN103017400A (en) * 2013-01-14 2013-04-03 西安交通大学 Compression/absorption type combined heat pump suitable for intelligent comprehensive urban energy resource regulation
CN103411347A (en) * 2013-08-27 2013-11-27 苏州新华软智能装备有限公司 Coupling type heat pump waste heat recovery system
US20140013783A1 (en) * 2012-03-09 2014-01-16 Bluelagoon Technologies Ltd. Apparatus and method for vapor driven absorption heat pumps and absorption heat transformer with applications
CN103649649A (en) * 2010-12-27 2014-03-19 特迈斯有限公司 Hybrid absorption-compression cooler
WO2014191230A1 (en) * 2013-05-31 2014-12-04 Siemens Aktiengesellschaft Cooling system and cooling process for use in high-temperature environments
WO2018067818A1 (en) * 2016-10-05 2018-04-12 Johnson Controls Technology Company Heat pump for a hvac&r system
WO2018129128A1 (en) * 2017-01-04 2018-07-12 Stone Mountain Technologies, Inc. Hybrid fossil fuel-electric multi-function heat pump
WO2018183238A1 (en) * 2017-03-27 2018-10-04 Rebound Technologies, Inc. Cycle enhancement methods, systems, and devices
DE102013014238B4 (en) 2013-08-27 2019-07-18 Audi Ag Air conditioning system for a vehicle with an adsorption storage
US10995993B2 (en) 2014-09-27 2021-05-04 Rebound Technologies, Inc. Thermal recuperation methods, systems, and devices
US11067328B2 (en) 2015-11-26 2021-07-20 Dometic Sweden Ab Hybrid cooling appliance
US11079184B2 (en) 2012-02-07 2021-08-03 Rebound Technologies, Inc. Methods, systems, and devices for thermal enhancement
CN113587471A (en) * 2021-06-21 2021-11-02 东南大学 Cold and hot confession system that allies oneself with of doublestage compression and absorption formula high temperature heat pump complex
CN114593476A (en) * 2022-03-07 2022-06-07 江苏科技大学 Solar refrigeration air-conditioning system and working method thereof
US11460226B2 (en) 2018-02-23 2022-10-04 Rebound Technologies, Inc. Freeze point suppression cycle control systems, devices, and methods
US11530863B2 (en) 2018-12-20 2022-12-20 Rebound Technologies, Inc. Thermo-chemical recuperation systems, devices, and methods

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JP2512095B2 (en) * 1988-08-12 1996-07-03 株式会社日立製作所 Cold heat generation method
JP3125796B2 (en) * 1995-03-10 2001-01-22 株式会社日立製作所 Cold water production equipment

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US3301000A (en) * 1965-02-15 1967-01-31 Borg Warner Combination vapor compression and absorption refrigeration system
US3824804A (en) * 1973-08-22 1974-07-23 C Sandmark Refrigerating machines
US4374468A (en) * 1980-03-18 1983-02-22 Matsushita Electric Industrial Company Absorption type refrigeration system including compressor driven auxiliary flow circuits isolated from main circuit

Patent Citations (3)

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US3301000A (en) * 1965-02-15 1967-01-31 Borg Warner Combination vapor compression and absorption refrigeration system
US3824804A (en) * 1973-08-22 1974-07-23 C Sandmark Refrigerating machines
US4374468A (en) * 1980-03-18 1983-02-22 Matsushita Electric Industrial Company Absorption type refrigeration system including compressor driven auxiliary flow circuits isolated from main circuit

Cited By (54)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4586344A (en) * 1984-10-23 1986-05-06 Dm International Inc. Refrigeration process and apparatus
EP0181137A3 (en) * 1984-11-05 1987-02-04 Calmac Manufacturing Corporation Method of cyclic air conditioning with cogeneration of ice
WO1988008107A1 (en) * 1987-04-09 1988-10-20 Scherer, Frank, J. Integrated cascade refrigeration system
US4819445A (en) * 1987-04-09 1989-04-11 Scherer John S Integrated cascade refrigeration system
USRE34030E (en) * 1987-04-09 1992-08-18 Frank J. Scherer Integrated cascade refrigeration system
US4745768A (en) * 1987-08-27 1988-05-24 The Brooklyn Union Gas Company Combustion-powered refrigeration with decreased fuel consumption
WO1989002056A1 (en) * 1987-08-27 1989-03-09 The Brooklyn Union Gas Company Combustion-powered refrigeration with decreased fuel consumption
US5018367A (en) * 1988-08-04 1991-05-28 Hitachi, Ltd. Cooling energy generator with cooling energy accumulator
US4966007A (en) * 1989-05-12 1990-10-30 Baltimore Aircoil Company, Inc. Absorption refrigeration method and apparatus
US5038574A (en) * 1989-05-12 1991-08-13 Baltimore Aircoil Company, Inc. Combined mechanical refrigeration and absorption refrigeration method and apparatus
EP0482738A1 (en) * 1990-10-26 1992-04-29 Baltimore Aircoil Company, Inc. Combined mechanical refrigeration and absorption refrigeration method and apparaus
US5212961A (en) * 1991-10-15 1993-05-25 Graf William J Dual cycle water chiller
US5163302A (en) * 1991-10-21 1992-11-17 General Motors Corporation Air conditioning system with precooler
US6141987A (en) * 1997-01-20 2000-11-07 Gaz De France Absorption refrigerating system and working mixture for said system
RU2344357C1 (en) * 2007-04-12 2009-01-20 ГОУ ВПО "Южно-Российский государственный университет экономики и сервиса" (ЮРГУЭС) Absorption/compression refrigeration unit
WO2010054537A1 (en) * 2008-11-17 2010-05-20 Su Qingquan Heat pump cycle system and combined supplying method of cold and heat
CN102216702B (en) * 2008-11-17 2012-11-21 苏庆泉 Heat pump circulation system and combined cooling and heating method
US20120031122A1 (en) * 2009-04-14 2012-02-09 Huayu Li Method to improve heating temperature of heat pump and second-type high temperature absorption heat pump
US8756946B2 (en) * 2009-04-14 2014-06-24 Huayu Li Method to improve heating temperature of heat pump and second-type high temperature absorption heat pump
KR101093919B1 (en) 2010-01-15 2011-12-13 엘지전자 주식회사 Vertical absorption chiller
US8820099B2 (en) 2010-01-19 2014-09-02 Atoll Energy Thermal power upgrade facility
WO2011089338A3 (en) * 2010-01-19 2011-10-27 Atoll Energy Thermal power upgrade facility
US20120011871A1 (en) * 2010-07-13 2012-01-19 Cameron International Corporation Compressor waste heat driven cooling system
US8474277B2 (en) * 2010-07-13 2013-07-02 General Electric Company Compressor waste heat driven cooling system
US8931291B2 (en) 2010-07-13 2015-01-13 Cameron International Corporation Compressor waste heat driven cooling system
US9372022B2 (en) 2010-07-13 2016-06-21 Ingersoll-Rand Company Compressor waste heat driven cooling system
CN103649649A (en) * 2010-12-27 2014-03-19 特迈斯有限公司 Hybrid absorption-compression cooler
WO2013021323A1 (en) 2011-08-05 2013-02-14 Innovation Factory S.R.L. Heat pump system and method of cooling and/or heating by means of said system
US11079184B2 (en) 2012-02-07 2021-08-03 Rebound Technologies, Inc. Methods, systems, and devices for thermal enhancement
US20140013783A1 (en) * 2012-03-09 2014-01-16 Bluelagoon Technologies Ltd. Apparatus and method for vapor driven absorption heat pumps and absorption heat transformer with applications
US9091469B2 (en) * 2012-03-09 2015-07-28 Tahoe Technologies, Ltd. Apparatus and method for vapor driven absorption heat pumps and absorption heat transformer with applications
CN103017400A (en) * 2013-01-14 2013-04-03 西安交通大学 Compression/absorption type combined heat pump suitable for intelligent comprehensive urban energy resource regulation
WO2014191230A1 (en) * 2013-05-31 2014-12-04 Siemens Aktiengesellschaft Cooling system and cooling process for use in high-temperature environments
CN103411347B (en) * 2013-08-27 2015-06-03 苏州新华软智能装备有限公司 Coupling type heat pump waste heat recovery system
DE102013014238B4 (en) 2013-08-27 2019-07-18 Audi Ag Air conditioning system for a vehicle with an adsorption storage
CN103411347A (en) * 2013-08-27 2013-11-27 苏州新华软智能装备有限公司 Coupling type heat pump waste heat recovery system
US10995993B2 (en) 2014-09-27 2021-05-04 Rebound Technologies, Inc. Thermal recuperation methods, systems, and devices
US11067328B2 (en) 2015-11-26 2021-07-20 Dometic Sweden Ab Hybrid cooling appliance
WO2018067818A1 (en) * 2016-10-05 2018-04-12 Johnson Controls Technology Company Heat pump for a hvac&r system
US11486612B2 (en) 2016-10-05 2022-11-01 Johnson Controls Tyco IP Holdings LLP Heat pump for a HVACandR system
WO2018129128A1 (en) * 2017-01-04 2018-07-12 Stone Mountain Technologies, Inc. Hybrid fossil fuel-electric multi-function heat pump
US12173910B2 (en) * 2017-01-04 2024-12-24 Stone Mountain Technologies, Inc. Hybrid fossil fuel-electric multi-function heat pump
CN110168293A (en) * 2017-01-04 2019-08-23 山石科技有限公司 Hybrid Fossil Fuel Electric Multifunctional Heat Pump
EP3566011A4 (en) * 2017-01-04 2020-08-26 Stone Mountain Technologies, Inc. HYBRID MULTIFUNCTIONAL HEAT PUMP WITH ELECTRICITY AND FOSSIL FUELS
CN110709652A (en) * 2017-03-27 2020-01-17 反弹技术有限公司 Loop enhancement method, system and device
US11473818B2 (en) 2017-03-27 2022-10-18 Rebound Technologies, Inc. Cycle enhancement methods, systems, and devices
US10584904B2 (en) 2017-03-27 2020-03-10 Rebound Technologies, Inc. Cycle enhancement methods, systems, and devices
WO2018183238A1 (en) * 2017-03-27 2018-10-04 Rebound Technologies, Inc. Cycle enhancement methods, systems, and devices
US11460226B2 (en) 2018-02-23 2022-10-04 Rebound Technologies, Inc. Freeze point suppression cycle control systems, devices, and methods
US11530863B2 (en) 2018-12-20 2022-12-20 Rebound Technologies, Inc. Thermo-chemical recuperation systems, devices, and methods
US12188717B2 (en) 2018-12-20 2025-01-07 Rebound Technologies, Inc. Thermo-chemical recuperation systems, devices, and methods
CN113587471A (en) * 2021-06-21 2021-11-02 东南大学 Cold and hot confession system that allies oneself with of doublestage compression and absorption formula high temperature heat pump complex
CN113587471B (en) * 2021-06-21 2022-06-28 东南大学 Double-stage compression and absorption type high-temperature heat pump combined cold and heat combined supply system
CN114593476A (en) * 2022-03-07 2022-06-07 江苏科技大学 Solar refrigeration air-conditioning system and working method thereof

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